Electron tube



June 16, 1936. BRUCHE 2,044,347

ELECTRON TUBE Filed Oct. 5, 1952 00000000 00000000 00000 000 ooooo/oooINVENT QR ERNST UC Patented June 16, 1936 1 UNITED STATES PATENT OFFICEELECTRON TUBE Ernst Briiche, Berlin-Reinickendorf, Germany,

assignor to Allgcmeine Elektricitatz Gesellschaft, Berlin, Germany, acorporation of Germany Application October 5, 1932, Serial No. 636,281In Germany October 19, 1931 1 Claim. (01. 25027.5)

The present invention relates to a new method conducting tube I whichhas an inside diameter and means to control an electron ray tube of theof 2 or 3 mm. has at one end a flared opening H cathode ray type for usein sound film and telewhich is placed opposite the heated cathode I2vision work. mounted inside the vessel 6. The conductive tube Inelectron ray tubes used for sound film and It] may at the same time beused to act as the television work the intensity of the spot producedanode by applying a suitable potential thereto by upon the tubefluorescent screen or end wall due means of the lead l3. The electronsemanating to the bombardment thereof by the cathode ray from the cathodeI2 are driven through the conhas heretofore been regulatedelectrostatically, ducting tube member ID and are made to impingeespecially the so-called Wehnelt cylinder having upon the fluorescentscreen I lmounted upon 10 been employed for this purpose. inside surfaceof the end wall of the vessel 1.

Instead of electrostatic control of the bright- By the aid of the coilI5 snugly surrounding the ness or luminosity of the resulting image spotconductive tube In it is thus feasible to influence recourse is badaccording to the present inventhe intensity f the electron y p In 0 tionto magnetic control. In controlling the ray er to insure as high asfeasible an intensity of 15 intensity in this manner the magnetic fieldof a the pencil by action of the coil, the latter is discoil traversedby the controlling currents and Posed most suitably at as close aProximity s whose axis coincides with the axis of the ray possible tothe outlet opening of the electron pencil is brought to act upon thelatter in such pencil 20, as illustrated in the drawing. Instead manneras to produce a controlling a ti th r of the conducting tube It? therecould also be used 0 on. In the practical application of this idea it isa glass tube rendered interiorly conductive, for

essential that the coil should surround the ray instance, by having a lvr ating applied to pencil in a similarly close manner as the Wehnelt einner Wall- In this case lGhe p 8 a d 9 cylinder. may be dispensed withsince the glass tube may The accompanying drawing serves to illustratebe united or fused directly with the cap members the general principlesof the invention and show 6 and 1.

two suitable forms of tube arrangements. By the Havin now described thev on What I drawing, Fig. 1 shows the magnetic field applied cla m is!close to the cathode and arranged somewhat like A cathode ray tubecomprising an evacuated a Wehnelt cylinder; and Fig. 2 illustrates amodicontainer, means within the container for gener- 30 fied controlarrangement using the same general ating a cathode ray, a secondcontainer having control principle. provided therein at one end afluorescent viewing Referring now to the drawing, and first to Fig.screen, an elongated tubular anode connecting 3 1, the cathode ray tubel is shown to include a the separate containers to permit the cathodecathode member 2, an anode member 3 and the ray pencil generated withinone container to be fluorescent screen 4 which is rendered luminouspassed therethrough to the second container, and by bombardment thereofby the cathode ray pencil electro-magnetic means surrounding the said.20. To regulate the intensity of the electron ray tubular anode in thespace between the two conpencil 20 there is provided a coil 5 whichsnugly tainers, said electro-magnetic means being adapt- 40 embraces orsurrounds the electron ray pencil ed to have applied thereto varyingmagnitude and which sets up interiorly a field which extends electricsignals for producing varying strength in the direction of the electronray pencil. magnetic fields along the axis of the tubular In anotherembodiment of the invention, such anode to vary in accordance with thevariations as that shown by Fig. 2, ways and means are in the electricalsignals the electron concentration 5 adopted to mount the coilexteriorly of the tube within the g at d C d y W thou d minwhile yet theelectron ray pencil is made to be ishing the total electron content ofthe ray so as closely surrounded by the coiL The cathode ray to controlthe observable intensity 0f the lumitube, according to thismodification, comprises nescent efiect produced upon the fluorescentviewtwo parts 5 and 1 which are closed by metal caps ing screen whilemaintaining constant the elec- 50 8 and 9, and which are inter-connectedby a contron flow toward the screenducting tube I0 fitted into themetallic caps. The ERNST BRI'lCHE.

